The Strange Science of Epigenetics

Some of the most interesting and exciting genetic research in recent years has focused on what’s called epigenetics. In brief, this is the process by which our genes are “turned on” and “turned off.”

Even though every cell in the body has the same genes, their expression (or activity) is controlled by the attachment or detachment of small molecules often referred to as regulatory tags. A liver cell and brain cell have very different tags, because only certain genes are needed for each cell type. But the really interesting thing about epigenetics is that the tags aren’t fixed in the same way the DNA sequence is: Some of them can change throughout your lifetime, and in response to outside influences.

Researchers recently found, for example, that babies born to women who smoked during their pregnancy have epigenetic tags on certain genes associated with embryonic development as well as nicotine dependence. A mother’s diet, nutritional status, body weight, and overall health during pregnancy may leave genetic tags that increase—or decrease— the risk of obesity, diabetes, and other conditions. Epigenetic tags caused by tobacco are believed to contribute to chronic obstructive pulmonary disease such as bronchitis and emphysema. It’s now thought that epigenetics may also be a factor in the development of Alzheimer’s disease, cardiovascular disease, and more than half of all cancers.

Scientists are trying to identify epigenetic changes and learn how to control their effects with, for example, diet or drugs. If this is possible, it could potentially lead to new ways to prevent cancer and reduce rates of obesity, diabetes, and other diseases.